1. Field of the Invention
This invention relates to cooling. More specifically, the invention relates to a formulation including a phase change material provided for intimate contact with a user's epidermis to cool the epidermis in response to increased heat.
2. Description of Related Art
Several products are commercially available that are intended to combat uncomfortable sensations experienced in response to bodily heating. For example, patches containing menthol or some other similar substance are provided for application by a user to the user's epidermis, to impart on the user a cooling sensation. Such patches are marketed for application to the forehead when running a fever or to an injury site, such as a sprain. Other sources of increased epidermal temperature also are known, for example, due to exercise, drug side effects or hormonal imbalances, including as a result of menopause.
Menthol-based and similar conventional cooling solutions, however, are single use and do not actually cool the body. Menthol creates the illusion of cooling because it activates TRPM8, a protein in the body that perceives cold. Once the menthol dissipates, it is gone though. Moreover, because menthol is only “tricking” the body into feeling cool, it does not actually create any epidermal temperature change.
Thus, there is a need for reusable or reversible cooling relief that a user can apply to a desired site on the epidermis.
There is a further need for fast-acting cooling relief with continued efficacy over an extended period of time.
There also is a need for cooling relief that lowers the temperature of the epidermis.
There is also a need for cooling relief that is activated by increasing skin temperature and can be reactivated every time the skin temperature increases over a 24-hour period without additional application.